PORT ST. LUCIE – Mo Vaughn sat in the home dugout at Thomas J. White Stadium, rubbing his shaved scalp, wringing his black cap in his hands and constantly describing the excitement contained within his hulking, 270-pound frame.

Vaughn’s workout uniform would remain hanging in his locker yesterday, but the new Mets first baseman immediately put on a symbolic suit of leadership upon his first morning in camp.

“Hopefully I’ll establish it tomorrow,” Vaughn said of his vaunted presence. “My main thing is to make it fun.”

Vaughn arrived at the park Monday night and unpacked with the help of manager Bobby Valentine. He dropped in yesterday morning to meet teammates, speak with the media and get his locker settled, but he won’t work out until today.

“To be here is nice, to finally see what you’ve been dreaming about all these weeks,” Vaughn said as his eyes danced and his grin appeared.

“Definitely when I put the uniform on and we stretch as a team, it’s going to really hit you.”

The 34-year-old former American League MVP is a tad fearful and anxious after missing last season with a ruptured left biceps tendon and getting traded from Anaheim, but he plans to weather the self-imposed pressure and enjoy this experience.

It goes with the territory of someone who can juggle daytime charity work with nightlife excursions.

“He’s definitely not going to shy away from the Atlanta staff, his duties on the field or his persona off the field,” Valentine said.

“Mo is who he is. I think that’s a good thing, too.”

Vaughn welcomes both the heat and the humidity. He’ll get plenty this season, figuratively and literally.

He wants to slim down 10 pounds between now and Opening Day, and figures this is the place to do it.

“One thing I love about being down here in Florida is you’re gonna sweat. It’s hot,” he said. “That’s what I liked about the East Coast: the humidity.

“I found myself on the West Coast, I couldn’t even work up a sweat. [Here] you can totally wake up in the morning and just feel it on you.”

Although much has been made of the feeling-out process, Vaughn believes chemistry develops quickly.

He’s already met John Franco’s family, bonded by phone with Roberto Alomar and bumped into Al Leiter in the city.

“These guys are good guys,” Vaughn said. “We don’t need a damn conference. We don’t need to go on a retreat.”

Leiter, for one, respects all that Vaughn brings.

“It’s always appreciated when you bring in not only a quality player but a quality person,” Leiter said.

“And being a quality person has many different facets to it, and in our sport and this game, leadership quality is one of them.”

Vaughn was expected to arrive with the other rehab players Friday, but was delayed by previous engagements.

He spent the last few days hanging with Mayor Bloomberg, chilling at Carnegie Deli while his namesake sandwich was unveiled and touring Tribeca before he found the perfect place: an apartment with a private elevator and an entire floor to himself.

Now he just has to figure out which furniture to move from his 6,000 square-foot spread near Boston and which stuff to give to his sisters.

“The thing about living in the city – you’re never there,” Vaughn said.